Subfemtotesla radio-frequency atomic magnetometer for nuclear quadrupole resonance detection

A method for detecting and representing a low intensity magnetic field in the radio-frequency (RF) range using an atomic magnetometer with sensing cell having a high sensitivity to the low intensity magnetic field, the method comprising the steps of:

• increasing magnetic polarization of alkali metal vapor included in the sensing cell to tune a Zeeman resonance of the alkali metal vapor to high frequency, thereby increasing the sensitivity of the alkali metal vapor to the low intensity magnetic field;
• reorienting the magnetic polarization of the alkali metal vapor using a magnetic field;
• probing the magnetic polarization of the reoriented alkali metal vapor to provide an output having characteristics related to the low intensity magnetic field;
• and
• determining the characteristics of the low intensity magnetic field from the output, and providing a representation of the characteristics of the low intensity magnetic field.

A high sensitivity atomic magnetometer for detecting and representing a low intensity magnetic field in the radio-frequency (RF) range, the magnetometer comprising:

• a sensing cell including an alkali metal vapor and a buffer gas, wherein the sensing cell is exposed to a background magnetic field to tune a Zeeman resonance of the alkali metal vapor to high frequency;
• a polarizing transmitter that increases a magnetic polarization of the alkali metal vapor, thereby increasing the sensitivity of the alkali metal vapor to the low intensity magnetic field, by laser illumination of the sensing cell in opposite directions of a single plane, wherein power of the laser is selected to provide a minimal half-width at half-maximum of the Zeeman resonance of the alkali metal vapor;
• a magnetizer that imposes a pulsed detuning magnetic field on a volume of space including the sensing cell that offsets the magnetic resonance frequency of the alkali metal vapor;
• a probing interrogator that probes the magnetic polarization of the alkali metal vapor, the interrogator providing an output from the alkali metal vapor that includes characteristics related to the low intensity magnetic field;
• and
• a measuring module that receives the output, determines the characteristics of the low intensity magnetic field, and provides a representation of the low intensity magnetic field.